ACFOX vs. AIOIX

Last updated Jun 4, 2026

ACFOX (American Century Investments Focused Dynamic Growth Fund) and AIOIX (American Century International Opportunities Fund) are both mutual funds - ACFOX is a Large Cap Growth Equities fund managed by American Century, while AIOIX is a Foreign Small & Mid Cap Equities fund managed by American Century. Over the past 10 years, ACFOX returned 19.58%/yr vs 8.30%/yr for AIOIX. A 0.70 correlation means they provide meaningful diversification when combined. ACFOX charges 0.85%/yr vs 1.48%/yr for AIOIX.

Performance

ACFOX vs. AIOIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Investments Focused Dynamic Growth Fund (ACFOX) and American Century International Opportunities Fund (AIOIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, ACFOX achieves a 9.28% return, which is significantly lower than AIOIX's 15.88% return. Over the past 10 years, ACFOX has outperformed AIOIX with an annualized return of 19.58%, while AIOIX has yielded a comparatively lower 8.30% annualized return.

ACFOX

• 1D: -1.06%
• 1M: 5.78%
• YTD: 9.28%
• 6M: 10.92%
• 1Y: 33.16%
• 3Y*: 28.29%
• 5Y*: 11.86%
• 10Y*: 19.58%

AIOIX

• 1D: -0.15%
• 1M: 2.46%
• YTD: 15.88%
• 6M: 18.09%
• 1Y: 32.80%
• 3Y*: 15.62%
• 5Y*: 2.92%
• 10Y*: 8.30%

*Multi-year figures are annualized to reflect compound growth (CAGR)

ACFOX vs. AIOIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
ACFOX American Century Investments Focused Dynamic Growth Fund	9.28%	20.51%	43.30%	35.66%	-36.32%	7.08%	73.31%	32.30%	6.51%	34.55%
AIOIX American Century International Opportunities Fund	15.88%	29.62%	1.31%	8.63%	-30.19%	5.79%	31.07%	28.95%	-22.19%	45.09%

Correlation

The correlation between ACFOX and AIOIX is 0.70, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.70
Correlation (3Y) Calculated over the trailing 3-year period	0.68
Correlation (5Y) Calculated over the trailing 5-year period	0.72
Correlation (10Y) Calculated over the trailing 10-year period	0.70
Correlation (All Time) Calculated using the full available price history since Jun 1, 2006	0.70

The correlation between ACFOX and AIOIX has been stable across timeframes, ranging from 0.68 to 0.72 - a consistent structural relationship.

Return for Risk

ACFOX vs. AIOIX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

ACFOX

ACFOX Risk / Return Rank: 34
ACFOX Sharpe Ratio Rank: 38
ACFOX Sortino Ratio Rank: 34
ACFOX Omega Ratio Rank: 34
ACFOX Calmar Ratio Rank: 30
ACFOX Martin Ratio Rank: 31

AIOIX

AIOIX Risk / Return Rank: 37
AIOIX Sharpe Ratio Rank: 35
AIOIX Sortino Ratio Rank: 32
AIOIX Omega Ratio Rank: 34
AIOIX Calmar Ratio Rank: 37
AIOIX Martin Ratio Rank: 44

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

ACFOX vs. AIOIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Investments Focused Dynamic Growth Fund (ACFOX) and American Century International Opportunities Fund (AIOIX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	ACFOX	AIOIX	Difference
Sharpe ratio: Return per unit of total volatility	1.80	1.73	+0.08
Sortino ratio: Return per unit of downside risk	2.43	2.36	+0.06
Omega ratio: Gain probability vs. loss probability	1.31	1.31	0.00
Calmar ratio: Return relative to maximum drawdown	2.05	2.32	-0.27
Martin ratio: Return relative to average drawdown	7.24	9.33	-2.09
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

ACFOX vs. AIOIX - Sharpe Ratio Comparison

The current ACFOX Sharpe Ratio is 1.80, which is comparable to the AIOIX Sharpe Ratio of 1.73. The chart below compares the historical Sharpe Ratios of ACFOX and AIOIX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	ACFOX	AIOIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.80	1.73	+0.08
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.47	0.16	+0.32
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.83	0.44	+0.39
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	0.55	+0.03

Drawdowns

ACFOX vs. AIOIX - Drawdown Comparison

The maximum ACFOX drawdown since its inception was -58.92%, smaller than the maximum AIOIX drawdown of -66.16%. Use the drawdown chart below to compare losses from any high point for ACFOX and AIOIX.

Drawdown Indicators

	ACFOX	AIOIX	Difference
Max Drawdown Largest peak-to-trough decline	-58.92%	-66.16%	+7.24%
Max Drawdown (1Y) Largest decline over 1 year	-16.52%	-14.00%	-2.52%
Max Drawdown (3Y) Largest decline over 3 years	-27.03%	-18.46%	-8.57%
Max Drawdown (5Y) Largest decline over 5 years	-43.77%	-41.19%	-2.58%
Max Drawdown (10Y) Largest decline over 10 years	-43.77%	-41.19%	-2.58%
Current Drawdown Current decline from peak	-1.06%	-1.86%	+0.80%
Average Drawdown Average peak-to-trough decline	-14.71%	-16.02%	+1.31%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.67%	3.47%	+1.20%

Volatility

ACFOX vs. AIOIX - Volatility Comparison

The current volatility for American Century Investments Focused Dynamic Growth Fund (ACFOX) is 5.17%, while American Century International Opportunities Fund (AIOIX) has a volatility of 6.73%. This indicates that ACFOX experiences smaller price fluctuations and is considered to be less risky than AIOIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	ACFOX	AIOIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.17%	6.73%	-1.56%
Volatility (6M) Calculated over the trailing 6-month period	14.56%	16.02%	-1.46%
Volatility (1Y) Calculated over the trailing 1-year period	18.80%	18.86%	-0.06%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	25.28%	18.91%	+6.37%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.81%	18.95%	+4.86%

ACFOX vs. AIOIX - Expense Ratio Comparison

ACFOX has a 0.85% expense ratio, which is lower than AIOIX's 1.48% expense ratio.

Dividends

ACFOX vs. AIOIX - Dividend Comparison

ACFOX's dividend yield for the trailing twelve months is around 6.91%, more than AIOIX's 0.24% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACFOX American Century Investments Focused Dynamic Growth Fund	6.91%	7.56%	0.00%	0.00%	0.00%	2.48%	0.62%	0.00%	0.00%	0.00%	1.15%	1.33%
AIOIX American Century International Opportunities Fund	0.24%	0.27%	0.32%	0.23%	0.00%	17.80%	3.18%	0.92%	5.28%	9.09%	0.04%	7.15%

Frequently Asked Questions

Can I hold both ACFOX and AIOIX in my portfolio?

ACFOX and AIOIX have a correlation of 0.70, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, ACFOX or AIOIX?

AIOIX has higher volatility (6.73%) compared to ACFOX (5.17%). In terms of maximum drawdown, ACFOX dropped -58.92% vs AIOIX's -66.16%.

Which has better risk-adjusted returns?

ACFOX currently has the higher Sharpe Ratio (1.80 vs 1.73), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.